This application requests funding in partial support of a FASEB Summer Conference entitled Gastrointestinal Tract X: Physiology and Pathophysiology of GI Epithelia to be held from July 19-24 in Tucson, AZ at the Omni Tucson Resort and Spa. The conference will be the tenth in a series of biennial meetings that have become one of the premier venues for the discussion of cutting-edge research related to gastrointestinal health and disease. The specific objectives of the meeting will be 1) to provide scientific programming at the forefront of research in digestive diseases and related areas, organized around the broad themes of the underlying pathophysiology of these diseases and the mechanisms that afford protection against them; 2) to integrate information obtained at the molecular level that will shed light on regulatory mechanisms that define the organ-level behavior of the gastrointestinal tract; 3) to encourage the active participation of junior investigators and trainees; 4) to provide a venue for meaningful interchanges between investigators interested in basic and clinical aspects of gastrointestinal biology and pathobiology; and 5) to incorporate perspectives from researchers working in areas outside mainstream gastroenterology and to encourage cross-fertilization and novel insights into questions relevant to digestive health and disease. Specific topics areas to be covered will include the assembly of multiprotein signaling complexes, the maintenance of epithelial polarity, pathogen interactions with the gastrointestinal epithelia, transcriptional control of protein expression, endocytosis in epithelial cell function, epithelial ion transport and barrier function, gastrointestinal stem cells, intestinal cell differentiation and trafficking in hepatocytes. In addition, to invited presentations, each session will be supplemented with at least one presentation from junior investigators selected from contributed abstracts. Additionally, the conference will present a session for junior investigators on granting which will include a mock study section meeting. This session will be moderated by Dr. Mushtaq Khan. As in previous meetings of this FASEB summer conference, participation will be encouraged and is expected from investigators throughout the global disciplines of gastroenterology, surgery, gastrointestinal physiology, cell biology and biochemistry.